This hospital-based case-control study determined the patterns of hernia, haematological profile, and predictive ability of blood cell indices. This aimed to determine the usefulness of CBC, a routine haematological assay in predicting herniation and strangulation in pre-surgery patients in a district hospital in Ghana. Our findings showed that hernia was prevalent (48.1%) among older subjects ≥ 53 years of age and its occurrence significantly increased with increasing age. These findings corroborate the findings of a similar study conducted by Ashindoitiang et al., [9] in which the highest burden of hernia was among older subjects, and they attributed this phenomenon to ageing-associated wasting of muscles which tend to facilitate the development of the hernia. This was consistent with other literature that suggest similar patterns in other forms of hernia [10].
The burden of hernia in males was enormous compared to that in females in the present study. This observation suggests an increased male susceptibility to hernia, by a male:female ratio of 6:1 which is similar to a study conducted in Nigeria [11]. Also, this finding is consistent with the findings of a study conducted in Russia which reported among other factors, age and male gender as risk factors for developing hernia [5]. This gender-associated difference in the overall hernia prevalence may be ascribed to increased involvement of males in more strenuous activities [2][12] like farming, whereas, females in most rural districts like the current study setting are responsible for less difficult routine household chores [12].
Furthermore, this study revealed a significantly increased burden of inguinal hernia among the cases and is consistent with existing literature that suggests inguinal hernia as the predominant type of abdominal wall hernia [13]. The increased occurrence of inguinal hernia is ascribed to the altered architecture of the abdominal wall in humans which may have resulted from evolutionary changes [14]. Inguinal hernia was more common in males, which is consistent with findings of another study [15] that suggests a high lifetime risk of inguinal hernia repair among males than females. Also, Ohene-Yeboah et al., [16] suggest that inguinal hernia is prevalent among males residing in some regions of sub-Saharan Africa and in Ghanaian rural settings where males are more likely to engage in activities that increase the pressure within the intra-abdominal region [9]. This increased abdominal pressure and its associated outcome may also result from gender-specific conditions like hyperplasia of the prostate gland in males [15]. Consequently, this weakens and cause damage to the transversalis fascia, and predisposes more males to inguinal hernia [9]. Furthrmore, damage to the transversalis fascia in inguinal hernia patients could also be ascribed to elevated amount of matrix metalloproteinases that promote the breakdown of collagen [9].
Also, inguinal hernia consistently increased with increasing age, which is consistent with a study conducted in Ghana [16]. However, our result is in contrast with another study from a developed country where children younger than 15 years were the most affected with inguinal hernia [17], and this young age-related susceptibility is not well elucidated.
The cases of strangulated hernia were predominantly (68.0%) of the inguinal type with peak incidence observed among males (73.9%) and subjects ≤ 26 years of age (75.0%). Similarly, a study conducted by Ohene-Yeboah and Dally [18] revealed 50.5% of inguinal hernia repairs at the Komfo Anokye Teaching Hospital in the same Region of Ghana to be of the strangulated type. In many rural communities in Ghana, men serve as sole providers for their families, and the knowledge of them not being able to work for some time cause them to delay in seeking surgical interventions to hernia. Consequently, such delays may result in complications like strangulation and bowel obstructions. To further buttress this assertion, Beltran et al., [19] suggest a relationship between the occurrence of stranlgulation and the time of manifestation of hernia to admission and surgery.
The current study revealed significant variations in some erythrocyte- and leucocyte indices across the groups of participants studied. In particular, among the erythrocyte indices, we observed significantly increased HgB, MCHC, and RDW-CV in the hernia subjects and these markers were higher in those with strangulation than non-strangulated hernia and control groups. The increased HgB levels in the hernia groups in this study are similar to that reported in a prospective study by Panzuto et al., [20] in Italy. The increased RDW-CV in the strangulated group is consistent with findings of Akturk et al., [8] which reported high RDW among patients with strangulated hernia indicating its usefulness in identifying strangulation among patients who may require urgent surgical remedy. The RDW provides information on erythrocyte anisocytosis, and its elevation suggests ineffective synthesis of erythrocytes which may be observed in haemoglobinopathies and some nutritional deficiencies (like iron-, cobalamin- or folate deficiency), increased haemolysis or following haemotransfusion [21]. Also, the variation in the size of erythrocytes could be due to pro-inflammatory cytokines which impede the maturation of erythrocytes by erythropoietin [8,20]. The suggested anisocytosis, therefore, may have resulted from inflammation-mediated discharge of the immature erythrocytes into circulation [8]. This could also account for the increased RBC although not significant, and HgB among the cases. Furthermore, although HCT and RBC levels did not significantly vary across the groups, both were increased among strangulated hernia patients, which together with the significantly increased levels of HgB, and MCHC may suggest haemoconcentration that may have resulted from strangulation. In addition, the formation of hernia on the muscles of the abdominal wall puts pressure on the associateted blood vessels, which can disrupt normal blood circulation and culminate in ischaemia in the affected tissue [19]. This ischemic stress could be the cause of the increased erythrocyte indices, as a result of compensation for reduced oxygenation in the strangulated tissue.
Among the biomarkers studied, only the erythrocyte indices showed significant predictive accuracy for the occurrence of hernia and strangulation. The MCHC, age, HgB, and RDW were sensitive biomarkers for predicting the occurrence of hernia, while strangulation in hernia was predicted with MCHC, HgB, and RBC. However, the reason for this is not well understood.
The present study, however, had some limitations. Firstly, it could not afford to estimate neutrophil-to-lymphocyte ratio (NLR) which is considered a biomarker for predicting the severity of adult strangulated inguinal hernia. Secondly, serum electrolytes to determine hydration status, and thirdly, collagen levels to assess connective tissue disturbance was not determined.